Using –enable-rust since this edition, and I don’t know when to use VC2015, because based on my present tests, firefox built using VC2013 runs more faster than using VC2015 ( in all tests ).

Compatible Changes different from Official Edition
1) Remove the plugin restriction in x64 edition ( back out Bug 1165981 )
2) Restore distribution/bundles support ( back out Bug 1144127 )
3) Restore general.useragent.override.[domain] support ( back out Bug 896114 )

About disable extension signing check
Because of Mozilla some changes ( I haven’t worked it out yet ), if you migrate from the same official edition to my build, you can’t enable the disabled unsigned extensions, when you notice that, you can enter about:config and toggle xpinstall.signatures.required option some times, then the disabled extensions will be enabled. If you update your edition from my older build, you don’t need toggle the option.